Lye Discount Saponification Chart for Superfatting Homemade Soap

If you want to make luxurious hydrating homemade soap you have to Superfat your recipe and this is achieved by creating a lye discount in your recipe. Whilst this may seem confusing at first there is an easy chart with which you can work so you know in the first instance how much Lye it takes to turn 1oz of oils and fats into the soap in the saponification process.

Soap Making Saponification Value Chart

This chart provides a list of fats and oils commonly used in soap making at 1oz values.

That is in the value in the lye column is how much lye is required to turn 1oz of oil into soap. You will need to calculate this value based on the amount of fat or fats used.

This chart must be used as a guide only and the specific and Current Saponification value [See below] gained from the specific oil that will be used

Oil or FatLye
Almond Oil0.1367
Aloe Vera Butter0.1788
Aloe Vera Oil0.1421
Avacado Butter0.1339
Avacado Oil0.1337
Babassu Nut Oil0.1749
Canola Oil0.1328
Castor Bean Oil0.1286
Cocoa Butter0.1378
Coconut Oil [Refined]0.1910
Coconut Oil [Hydrogenated]0.1910
Coconut Oil [Fractionated]0.2321
Corn Oil0.1368
Evening Primrose Oil0.1362
Flaxseed Oil0.1358
Goose Fat0.1349
Grapeseed Oil0.1321
Hazelnut Oil0.1369
Hempseed Oil0.1359
Linseed Oil0.1358
Olive Oil0.1353
Palm Oil0.1420
Peanut Oil0.1367
Pumpkin Seed Oil0.1389
Rapeseed Oil0.1328
Sesame Seed Oil0.1336
Shea Butter0.1296
Sunflower Seed Oil0.1358
Beef Tallow0.1419
Sheep Tallow0.1384
Walnut Oil0.1349

How to find the Current Saponification Value

Whilst the chart above has some definite figures for the saponification formula, they are based on only a single source or average of the value across a range of saponification values for each oil.

In this I mean that two different batches of oil may have come from different crops and therefore will differ slightly in their make, slightly adjusting the exact saponification value of one batch against another, even from the same manufacturer.

You can find the SAP value of your desired oil as it should be on the packaging of the product you are buying. if it is not present then choose an alternative brand or product so you know the exact value.

How to use the SAP chart for Superfatting

I have a complete article on the full process for superfatting your homemade soap and the steps and calculations to carry out

Simply put, superfatting is when you discount the lye from the SAP value as provided. This means that you will use less lye than required to saponify all of the oil in your soap ensuring that excess oil [but not too much] is left over.

Leftover oil in your soap at the right level will not inhibit the lather but provide that little extra hydration to your skin when used.

Use Weight – Not Volume

You should always use weight as your measure when making homemade soap and specifically when using the saponification value chart.

If you measure the oil by ounces then also weigh the lye by ounces. If you prefer to use grams then both should be measured this way.

Do not rely on ‘cups’ to measure your oil and lye, always use some digital scales, remembering the tare weight, to ensure you get the exact weight measurement for your ingredients.

Too Much Oil – Not Too Much Lye

It is super important to remember that you will b reducing the amount of lye and having leftover oil in your soap when superfatting rather than the other way round.

Whilst you are more likely to run your soap and render it unusable if too much oil is left after saponification, having too much lye will still leave you with usable soap but excess lye which could irritate your skin.

So it is always Lye that is discounted to remove the danger of a bar of soap that would be harsh on your asking and produce a hydrated bar with excess oil that is beneficial.

Superfatting is not essential, and for beginners, you should practice getting your saponification levels exact and master the art of making your regular soap before attempting superfatting.

Safety First

Remember lye is a caustic substance, hence, ‘caustic soda’ and should be used with care and with the correct and full safety protection equipment including gloves, goggles, and long sleeves.

Also, when you have your final amount of lye required for saponification and the rest of your ingredients in cold process soap making, you will have to create your own lye solution by mixing it with distilled water.


Because of the thermogenic chemical reaction when water and Lye are mixed together it is super important to add the lye slowly to the water and not the other way round.

Adding water to the lye creates a faster reaction, more heat and a crust can appear on the top of the mix holding in the heat and gases with the potential to create a volcanic effect.

You’ll only make this mistake once and remember not to do it again, but if you can avoid it altogether you’ll have less of a fright and less mess to clean up.


I hope this chart will be of help when looking to create the right mix of lye and oils for saponification and your soap creation, remember to check each specific oil you use for the SAP value, and feel free to read more in my homemade soap section where many more aspects of this fun hobby can be discovered. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to, or

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